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In the JWT token there is a field 'aud', or audience, which function
is to state for which client(s) that token is intended.<br>
Currently (TokenManager:433) this is set to the client id:<br>
<tt><br>
token.audience(client.getClientId());</tt><tt><br>
</tt><br>
This seems fine in general, but we would like to have a token with
multiple entries in the audience field. This is possible and an
array value is even claimed to be the 'general case':
<a class="moz-txt-link-freetext" href="https://tools.ietf.org/html/rfc7519#section-4.1.3">https://tools.ietf.org/html/rfc7519#section-4.1.3</a> (where one single
value is the 'special case')<br>
<br>
Background is that we have a Keycloak running for a login of a
frontend that talks to multiple different resource servers. We'd
prefer to use one token for all of those resource servers. The
resource servers use Spring Security, which explicitly checks that
the 'name' you give to your Spring service is matched by (a value
of) the audience field of the JWT token. So now we have to give all
resource servers the same 'name', which doesn't feel right.<br>
<br>
So we need some way to influence the value of the audience field.
This could be achieved by following this RFC:
<a class="moz-txt-link-freetext" href="https://tools.ietf.org/html/draft-tschofenig-oauth-audience-00">https://tools.ietf.org/html/draft-tschofenig-oauth-audience-00</a> which
suggests to include a parameter to the request for the token. But
that RFC does not consider multiple values for the audience. Another
option would be to add an audience field in the settings of a Client
in Keycloak. Which would, if set, define the audience field of the
JWT token. This could be a comma separated string value that would
translate to a JSON array. A question about this could be: 'then
where to leave the client id?'. As suggested by this:
<a class="moz-txt-link-freetext" href="https://stackoverflow.com/questions/32013835/client-id-or-multiple-audiences-in-json-web-token">https://stackoverflow.com/questions/32013835/client-id-or-multiple-audiences-in-json-web-token</a>
the best place to put the client id is in the 'azp' field
(authorized party).<br>
<br>
<a href="https://tools.ietf.org/html/draft-tschofenig-oauth-audience-00" class="external-link" rel="nofollow"></a>Does the KeyCloak team
see this as a valuable addition? Will it be implemented somewhere in
the future? Or can we make a pull request ourselves that will be
merged?<br>
<br>
Thanks, Erik<br>
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